Implementation of the circular economy is beginning to become a reality and the early stages of product design are crucial for a proper adoption of the circular model. However, several studies claim that sustainability requirements usually decrease creativity. Therefore, it is necessary to help designers to think in a more circular manner and, at the same time, not compromising the creativity.

In this research, we study if creativity and circularity of the design outcomes change depending on whether circular requirements are applied as guided questions during the idea generation. For this purpose, an experiment has been carried out in which 20 engineering design students’ teams propose a novel idea for a product. Half of the teams received some circular economy requirements in the form of explicit guided questions, while the other half did not. The novelty, usefulness and feasibility of the design outcomes are assessed to measure creativity. Circularity is determined by accounting the number of items to slow, close and narrow loops at each design proposal.

The results indicate that explicitly introducing guided questions leads to no significant differences in creativity or circularity. However, it does lead to more dispersed circularity results. So, applying circular requirements explicitly in the form of guided questions does not worse creativity in comparison to when these requirements are implicit.

This work offers new results on the effect of circular requirements in the generation of ideas. These findings are useful for the management of design teams in companies and also for design teaching.

实施循环经济已开始成为现实，产品设计的早期阶段对于正确采用循环模型至关重要。但是，一些研究声称可持续性要求通常会降低创造力。因此，有必要帮助设计师以更循环的方式思考，同时又不影响创意。

在这项研究中，我们研究设计结果的创造力和圆度是否会根据在创意产生过程中是否将循环需求作为指导性问题而改变。为此，进行了一项实验，其中20个工程设计专业的学生团队提出了一种新颖的产品创意。一半的团队以明确的指导性问题的形式收到了一些循环经济要求，而另一半则没有。设计成果的新颖性，实用性和可行性被评估以衡量创意。通过考虑每个设计提议中慢速，闭合和狭窄循环的项目数量来确定循环性。

结果表明，明确引入指导性问题不会导致创造力或循环性的显着差异。但是，这确实导致更分散的圆度结果。因此，与隐含这些需求相比，以指导性问题的形式显式应用循环需求不会降低创造力。

这项工作提供了关于循环需求在思想生成中的效果的新结果。这些发现对于公司设计团队的管理和设计教学很有用。